Embodiments of the present specification relate generally to magnetic resonance imaging (MRI) systems, and more particularly to a diagnostic device and a method for diagnosing a faulty condition in a gradient amplifier of a MRI system.
In just a few decades, the use of magnetic resonance imaging (MRI) scanners has grown tremendously. MRI scans are being increasingly used to aid in diagnosis of multiple sclerosis, brain tumors, torn ligaments, tendonitis, cancer, strokes, and the like. As will be appreciated, MRI is a noninvasive medical test that aids physicians in the diagnoses and treatment of various medical conditions. The enhanced contrast that an MRI scan provides between the different soft tissues of the body allows physicians to better evaluate various parts of the body and determine presence of certain diseases that may not be assessed adequately with other imaging methods such as X-ray, ultrasound, or computed tomography (CT).
Typically, a MRI system includes a gradient driver, an output filter, and gradient coils. Further, the gradient driver is configured to excite the gradient coils located around an object, for example a patient, to generate gradient magnetic fields along one or more directions. To generate adequate gradient magnetic fields within a short period of time, the gradient driver is designed to drive a high current and a high voltage to the gradient coils through the output filter. The high current may be around 1000 A and the high voltage may be around 2000V, for example. Also, it is desirable to operate the gradient driver at a high switching frequency to reduce size of the output filter coupled to the gradient coil. However, operating the gradient driver at a high switching frequency with high current and high voltage may impose thermal stress on the gradient coil and the output filter. As a result, the gradient coil and/or components in the output filter may be adversely impacted.
In a conventional MRI system, the gradient drivers/amplifiers are turned OFF and electrical connections are disconnected to diagnose failed or damaged components in the system. Also, an external device, such as an analyzer is required to characterize a parameter of the system to diagnose a faulty component in the system. However, using the analyzer to diagnose the faulty component is a complicated technique and may not be accurate as the fault detection is preformed offline or when the system is turned OFF.